Handle Invalid GIT_EDITOR

[wookie184]

Noticed because of this: microsoft/vscode#153246

This error is raised when running blurb with an invalid GIT_EDITOR environment variable ("c:\Users\wookie184\AppData\Local\Programs\Microsoft VS Code Insiders\resources\app\extensions\git\dist\git-editor.sh" on windows in my case).

PS C:\Users\wookie184\Documents\GitHub\cpython> blurb
Traceback (most recent call last):
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\runpy.py", line 197, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\Users\wookie184\AppData\Local\Programs\Python\Python39\Scripts\blurb.exe\__main__.py", line 7, in <module>
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\site-packages\blurb.py", line 1659, in main
    sys.exit(fn(*filtered_args, **kwargs))
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\site-packages\blurb.py", line 935, in add
    subprocess.run(args)
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\subprocess.py", line 505, in run
    with Popen(*popenargs, **kwargs) as process:
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\subprocess.py", line 951, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "c:\users\wookie184\appdata\local\programs\python\python39\lib\subprocess.py", line 1420, in _execute_child
    hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
OSError: [WinError 193] %1 is not a valid Win32 application

It isn't very clear to the user what the issue is from this error. Possible solutions:

• Handle the error and reraise a specific error mentioning what failed to run (e.g. that GIT_EDITOR was invalid if that is the case).
• Handle the error and try to use a fallback (e.g. notepad on windows) if GIT_EDITOR fails.

If we decide to do one of these I'd be happy to try implementing it.

Thanks!

[hugovk]

Thanks for the report and sorry for the long delay in answering!

Do you know if VS Code still sets a .sh file as GIT_EDITOR? It looks they've fixed it? microsoft/vscode#153246 (comment)

---

We do have some fallbacks, first in find_editor which will fall back to notepad.exe on Windows if there's no editor env var set:

blurb/src/blurb/blurb.py

Lines 802 to 818 in 65941da

	def find_editor():
	for var in 'GIT_EDITOR', 'EDITOR':
	editor = os.environ.get(var)
	if editor is not None:
	return editor
	if sys.platform == 'win32':
	fallbacks = ['notepad.exe']
	else:
	fallbacks = ['/etc/alternatives/editor', 'nano']
	for fallback in fallbacks:
	if os.path.isabs(fallback):
	found_path = fallback
	else:
	found_path = shutil.which(fallback)
	if found_path and os.path.exists(found_path):
	return found_path
	error('Could not find an editor! Set the EDITOR environment variable.')

But in this case, it is set.

And then later, also check the editor file exists:

blurb/src/blurb/blurb.py

Lines 857 to 862 in 65941da

	if shutil.which(editor):
	args = [editor]
	else:
	args = list(shlex.split(editor))
	if not shutil.which(args[0]):
	sys.exit(f"Invalid GIT_EDITOR / EDITOR value: {editor}")

But in this case, it does exist.

So I think we could do one of your suggested options, if we think it's likely to occur again (although we've not had any other reports for this or reactions to this issue).